Partner Product

Model 6231  (147)
The Model 6231 is a general-purpose 16-channel narrowband digital receiver VIM-2 module. It attaches directly to VIM-compatible processor boards and connects directly to two processors.

Front End

Model 6231 accepts two analog RF inputs

at +4 dBm full scale into 50 ohms on front

panel SMA connectors. Amplifier bandwidth

of 90 MHz supports direct IF undersampling.

Each input is amplified and, optionally,

lowpass filtered to remove out-of-band signals

and prevent aliasing. The filters may be bypassed

for undersampling applications.

Optionally available, transformer-coupled

inputs reduce distortion for input signals

above 10 MHz and are recommended for IF

undersampling applications.

Each of the two inputs is then digitized by

a 14-bit A/D converter which is capable of

operating at sample rates up to 65 MHz

(Analog Devices AD6644) or, optionally,

80 MHz (AD6645). The A/D converter

clock can be driven from an internal 64 MHz

or 80 MHz crystal oscillator, or from an external

sample clock supplied through a front

panel SMA connector.

Digital Downconverters

The 6231 includes four Graychip GC4016

quad narrowband downconverter chips.

The maximum input sampling rate for the

GC4016 is 80 MHz. Each device includes

four independently tuned receiver channels

capable of center frequency tuning from DC

to 32 MHz, and with output bandwidths

ranging from 3.2 kHz to 1.6 MHz (for 64 MHz

sample clock).

Each GC4016 accepts four 14-bit parallel

inputs from the two A/D converters. Internal crossbar switches allow all 16 channels

on the board to select either of the A/D inputs

for flexible switching.

Synchronization

The front panel clock and sync bus allow

one 6231 to act as a master, driving the

sample clock out to a front panel cable bus

using LVDS differential signaling. Multiple

slaves can then be clocked synchronously

with the master. Additional sync lines allow

synchronization of the local oscillator phase,

frequency switching, decimating filter phase,

and FIFO data collection on multiple 6231’s.

147
*Two 65 or 80 MHz, 14-bit A/D converters *Optional front panel FPGA I/O connector *All downconverters can select any of the two inputs *90 MHz input bandwidth *3.2 kHz to 1.6 MHz output bandwidths for ƒs = 64 MHz *Front panel clock and sync bus synchronize multiple boards *See Model 7131 for PMC version
Model 6231
Front End Model 6231 accepts two analog RF inputs at +4 dBm full scale into 50 ohms on front panel SMA connectors. Amplifier bandwidth of 90 MHz supports direct IF undersampling. Each input is amplified and, optionally, lowpass filtered to remove out-of-band signals and prevent aliasing. The filters may be bypassed for undersampling applications. Optionally available, transformer-coupled inputs reduce distortion for input signals above 10 MHz and are recommended for IF undersampling applications. Each of the two inputs is then digitized by a 14-bit A/D converter which is capable of operating at sample rates up to 65 MHz (Analog Devices AD6644) or, optionally, 80 MHz (AD6645). The A/D converter clock can be driven from an internal 64 MHz or 80 MHz crystal oscillator, or from an external sample clock supplied through a front panel SMA connector. Digital Downconverters The 6231 includes four Graychip GC4016 quad narrowband downconverter chips. The maximum input sampling rate for the GC4016 is 80 MHz. Each device includes four independently tuned receiver channels capable of center frequency tuning from DC to 32 MHz, and with output bandwidths ranging from 3.2 kHz to 1.6 MHz (for 64 MHz sample clock). Each GC4016 accepts four 14-bit parallel inputs from the two A/D converters. Internal crossbar switches allow all 16 channels on the board to select either of the A/D inputs for flexible switching. Synchronization The front panel clock and sync bus allow one 6231 to act as a master, driving the sample clock out to a front panel cable bus using LVDS differential signaling. Multiple slaves can then be clocked synchronously with the master. Additional sync lines allow synchronization of the local oscillator phase, frequency switching, decimating filter phase, and FIFO data collection on multiple 6231’s.
N
Hardware
The Model 6231 is a general-purpose 16-channel narrowband digital receiver VIM-2 module. It attaches directly to VIM-compatible processor boards and connects directly to two processors.